318 
NATJTILOIDEA. 
Nautilus regalis, J. de C. Sowerby. 
? 1823. Nautilus reyalis, J. Sowerby, Min. Conch, vol. iv. p. 77, 
pi. ccclv. 
? 1825. Nautilus regalis, Defiance, Diet, des Sciences Naturelles, 
vol. xxxiv. p. 300. 
1836. Nautilus regalis^ 'Wetherell, London, Edinburgh, and Dublin 
Phil. Mag. and Joum. Sci. vol. ix. p. 465. 
? 1837. Nautilus BuHini, Galeotti, M^in. sur la Constitution G^og- 
nostique de la Province de Brabant, p. 140. (Figured by Burtin, 
Oryctographie de Bruxelles, 1784, p. 102, pi. xiv.) {Fide d'Or- 
bigny. Prodr. de Paleont. Stratigr. vol. ii. 1850, p. 338.) 
1843. Nautilus regalis, J. de C. Sowerby, Min. Conch, vol. vii. p. 35, 
pi. dcxxvii. f. 5 (erroneously marked 6 in some copies of the book). 
1849. Nautilus regalis, Edwards, Mon. of the Eocene Cephalopoda and 
Univalves of England, vol. i. (Pal. Soc.) p. 46, pi. iv. 
1849. Nautilus regalis, Dixon, Geology and Fossils of the Tertiaiy and 
Cretaceous Formations of Sussex, pp. 121, 228. 
1850. Nautilus regalis, d'Orbigny, Prodr. de I’al^ont. Stratigr. vol. ii. 
p. 338. 
1852. Nautilus regalis, Giebel, Fauna der Vorwelt, Band iii. Abth. i. 
p. 156. 
1854. Nautilus regalis, Morris, Cat. of British Fossils, 2nd ed. p. 306. 
1854. Nautilus regalis, Pictet, Trait5 de Pal^ontologie, 2nd ed. vol. ii. 
p. 629. 
? 1858. Nautilus regalis, Ooster, Cat. des Cephalopodes Fossiles des 
Alpes Suisses, pt. iii. p. 17. 
1872. Nautilus regalis, Whitaker, Geology of the London Basin, Mem. 
Geol. Surv. of England and Wales, Appendix, p. 589. 
1890. Nautilus regalis, Foord and G. C. Crick, Ann. Mag. Xat. 
Hist. ser. 6, vol. v. p. 391. 
Sp. Char. “ This species is distinguishable from the preceding 
\_N. centralis'] by the closed umbilicus, and by its general form, 
which is less ventricose than that of N. centralis. It is a smooth 
shell, flattened on the sides and bluntly rounded, and obscurely 
undulated on the ventral aspect. The aperture presents a sub- 
quadrate appearance. The umbilicus is closed by a thickening of 
the lip, assuming the appearance of a solid axis to the shell. The 
septa are nearly simple, presenting on each side slight undulations, 
and the short rounded dorsal lobes are deeply concave, and not 
reflected. In the young shell the septum is characterized by a 
conical depression [= inner or dorsal lobe of the sutures] placed on 
the dorsal margin close to the preceding whorl ; as the shell enlarges 
this gradually decreases in size and depth, and ultimately disappears. 
It was, of course, moulded on a corresponding protuberance on the 
